Technique Tuning Turbo effect on MPG

[Mach_Effect]

I am considering a TT Turbo for my 330i. For those of you who have the kit, how did the kit change your gas mileage for daily driving? I know gas mileage is a function of how you drive or how often you use boost but lets say you are simply cruising on the highway, how does your MPG compare before bolting on the kit? I bought the 330i because it is well balanced as far as power and gas mileage goes. If the kit drops fuel mileage considerably then I might as well get an M3.

Responses to the effect of "if you are concerned with gas mileage you should not consider a turbo" are neither requested nor appreciated. :P

[Novare330]

PM bluejeansonfire, he gets about 30 highway or something like that, but it all depends on how much you dog it and how hard you beat on your car to be honest

[aggieE46]

Remember, when you increase volumetric efficiency, you increase MPG. It's the part when you're getting up to cruising speed that will suffer. Around town will be worse, highway should be the same or better.

[BimmerDude18]

Yeah, Julio got 32 mpg when he was staying out of it and going 70.

I don't think you'll see much effect on highway economy, in town its going to be worse, you'll be hitting boost all the time and getting a sh!t eating grin too often to keep the high MPG's.

[bluejeansonfire]

I have managed as much as 30mpg while cruising at 85mph in 6th gear. my final drive ratio is 3.38, and 6th is .85. With a 5 speed, you'll manage similar numbers with a stock 2.93 diff. The gas mileage between my car and an M3 is incomparable on the highway. In the city, if I speed around town in boost, but not a lot, I can still manage low twenties/high teens. If I try to stay fully off-boost I think 23-25 could be achieved. But most of the time, very regularly I see full boost, so my gas mileage is in the low teens round town. This gas mileage is to the point that if you speed around town, only boosting a few pounds, being as fast as an e46 m3, you'll burn a comparable amount of gas to an e46 m3, but if you want to go faster, and you have plenty of grunt to go faster with this turbo kit, it'll require more gas. To give you an idea, I pulled ~2 cars last night on an Evo 9 dynoed at 350whp, from 60-120- granted my kit is not in "base" trim, but I'm certainly not very far at all, my kit is a stage "1.5".

The comments about gas mileage concerns are more appropriate to those considering a supercharger. I've compared my gas mileage when coming back from angiefest, 4 boosted nonMs riding together. With the combination of gearing and turbo, I had by far the best mileage. The e36 325is had a 5 speed, so his mileage wasn't as good. The other two were centrifugal supercharged, and they were a full quarter-third tank more empty than me when refilling.

The torque between a turbo 330 and an M3 will never compare- the m3 can not compete in that dept.

[Mach_Effect]

Thanks everyone for the info:). It is good to know that after the damage of 7 grand that I wont have to suffer too much more damage at the gas pump.

I like turbos because I think the idea of using wasted energy from exhaust gases is a much more efficient design compared to a supercharger that uses fuel to turn an additional pulley. Your comment about superchargers burning more fuel reaffirms my hypothesis. Thanks again.

[funkyman]

Thanks everyone for the info:). It is good to know that after the damage of 7 grand that I wont have to suffer too much more damage at the gas pump.

I like turbos because I think the idea of using wasted energy from exhaust gases is a much more efficient design compared to a supercharger that uses fuel to turn an additional pulley. Your comment about superchargers burning more fuel reaffirms my hypothesis. Thanks again.

Anything that uses a pulley like the AC will always use more fuel.Turning off the AC usually ,will give you a slight increase in power,pull,hp whatever you want to call it,not to mention more torque for your money,torque is the way to go baby.:pimpin: